AWWA C Disinfecting Water Mains. Current; Document Language: English; Published By: American Water Works Association (AWWA). This standard presents essential procedures for the disinfection of new and repaired potable water mains. All new water mains shall be disinfected before they. FIELD CHLORINATION. • AWWA/ANSI C – Disinfecting Water Mains. • First standard approved Sept. 30, • Latest revision June 1.
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Tags Environment and energyDrinking water. If final disinfectant residual is less than 0. For new watermains with limited sampling points available, an alternative method of collecting Microbiological samples is called staged sampling.
Pipe and Repair Parts disinfected? This definition does not include recharging the watermain or a requirement to achieve scouring velocity within the watermain. Category 1 watermain breaks are not defined as an observation of improper disinfection in accordance with Section of Schedule 16 stadnard O.
The requirements in this section also apply to temporary watermains.
Watermain disinfection procedure
Operating authorities shall use Certified Operators for functions that must be performed by a Certified Operator. When performing maintenance and repair activities as per sections 1. Operating Authorities may choose to provide notification to, or seek advice from, the local Medical Officer of Health at any time. This document outlines procedures for disinfecting water mains as part of an addition, modification, replacement, extension, planned maintenance, or emergency repair in a municipal residential drinking water system.
Examples of typical steps for Category 1, 2 and for special cases are attached as Tsandard C, D and E respectively. If chlorine disinfection was used, indicate initial concentration, contact time, final concentration stanvard final concentration as percentage of initial concentration. Dechlorination of discharged water is required for any water that is directed into surface water or if the discharge into the natural environment causes or is likely to cause an adverse effect, as aawa Condition 10 of Schedule B of the Municipal Drinking Water Licence.
Upon completion of the excavation, the Operator-in-Charge OIC shall conduct a visual inspection to determine the nature of the sgandard. Appendix E The following flowchart depicts the requirements for special case Contamination sewage or chemical as a result of a watermain break.
Example 3 When xtandard the slug method of chlorination, with a minimum contact time of 3 hours, the chlorine concentration shall be stzndard in the slug at the beginning of the disinfection process, as the slug moves through the watermain, and at the point of discharge. Flow may be discontinued after an Air gap has been created. This procedure also establishes minimum standards for record keeping, and notification to the Ministry and the local Medical Officer of Health.
Skip to main content. Contamination is typically not suspected for circumferential breaks or small leaks where flow is maintained from the break until an Air gap is established and where the Air gap is maintained during the repair procedure. The procedures are required to be followed in order to satisfy conditions imposed by the Director in a zwwa water works permit.
Examples of watermain breaks that are typical of Category 1 are included below for illustrative purposes only:.
AWWA C / AWWA C / AWWA C – Disinfection Of Water Package
Appendix D The following flowchart is an example of the typical steps required for Category 2 watermain breaks. If an operating authority believes that contaminated water was directed to users, this will constitute an observation of improper disinfection in accordance with Section of Schedule 16 etandard O. Notification to the local Ministry office is not required for Category 2 watermain breaks unless: In developing these procedures, operating authorities may use best management practices that go beyond the minimum requirements standxrd this document.
Mechanical removal of Contaminants; Flushing into the excavation; Higher velocity flushing after repairs where practical standarv feasible. This section does not require that all of the information be recorded on a single form: Drinking water system operating authorities shall ensure that emergency repairs to watermains and Appurtenances are undertaken in accordance with this procedure by any person authorized to perform the repairs. Spiral watermain break with evident Contamination.
Examples of watermain breaks that are typical of Category 2 are included below for illustrative purposes only:. The reporting and corrective actions of Schedule 16 and the applicable Schedule 17 or 18 of O.
Watermain disinfection procedure |
Flushing shall be conducted following repairs by creating a temporary dead end downstream of the break through valve operation, and Flushing through the location of the repair to a discharge point. The operating authority shall determine if flow can be maintained to the break site until the watermain is excavated. Flushed water may be discharged from a hydrant, plumbing or Appurtenances. The disinfection requirements for new watermains as per Section 1.
Watermain breaks with evident or suspected Contamination are classified as Category 2. The sampling plan shall include as a minimum taking two sets of Microbiological samples at least 24 hours apart.
The discharged water is deemed to be c6511 Class II spill for the purposes of O. Operating authorities may choose to provide notification to, or seek advice from, the local Medical Officer of Health at any time.
Notification to the local Ministry office is not required for Category 2 watermain breaks unless:. The sampling will typically occur at the point of Flushing, and may xwwa place from sgandard ports, hydrants, blow-offs, or premise plumbing.
For all other types of cleaning e. Category 2 watermain breaks are not required to be reported to the Spills Action Centre unless an operating authority believes that contaminated water was directed to users. Follow the steps described in section 3.